Understanding the Internet and its Services
1. What is the Internet?
The internet is a decentralized network of interconnected communication networks using the TCP/IP protocol family. This allows diverse physical networks to function as a single, global logical network. Its origins trace back to 1969 with the creation of ARPANET, initially used for defense communication during wartime in the USA.
While often confused, the internet and the World Wide Web (WWW) are distinct. The WWW, developed in 1990, is a set of protocols enabling easy access
Read MoreSoftware Development Best Practices
Security
Software security is the idea of engineering software to function correctly, even under malicious attack.
Addressing security early helps avoid vulnerabilities. DevSecOps is a good example of this. However, security adds cost and time to development.
Terminology:
- Defects: Deviation from requirements.
- Bugs: Implementation-level errors that can be detected and removed.
- Flaws: Deeper problems instantiated in code or absent at the design level (e.g., poor error handling exposing sensitive data).
- Failures:
Divide and Conquer & Recurrences Cheat Sheet
Maximum Subarray Sum Problem (1D):
– **Problem**: Given an array \( A \) of size \( n \), find the subarray with the maximum sum.
– **Definitions**:
– **Max Subarray Sum**: \( \text{max}_{l, u} \sum_{j=l}^{u} A[j] \)
– **Max Prefix Sum**: \( \text{max}_{u} \sum_{j=0}^{u} A[j] \)
– **Max Suffix Sum**: \( \text{max}_{l} \sum_{j=l}^{n-1} A[j] \)
– **Algorithm (Divide and Conquer)
**:
1. Divide array into two halves.
2. Recursively compute max subarray for the left and right halves.
3. Combine
A Guide to Effective Public Speaking and Presentations
Public Speaking and Presentations: A Comprehensive Guide
Engaging Your Audience
Visual contact is paramount. Avoid looking everywhere at once; instead, focus on individuals within the audience, making eye contact with different people in turn. This allows you to gauge their reactions and adapt your style accordingly.
Disagreement or fatigue from the audience should be used to calibrate the flow of your speech. Change your tone, language, and content dynamically if the audience seems bored or annoyed.
Read MoreUnderstanding I/O Techniques: Programmed, Interrupt & DMA
Data Transfer Modes with Peripherals
Data transfer to and from peripherals can be handled in three ways:
- Programmed I/O
- Interrupt-Initiated I/O
- Direct Memory Access (DMA)
Programmed I/O
This method relies on I/O instructions within a computer program. Each data transfer is initiated by a specific instruction, typically moving data between a CPU register and memory. Programmed I/O requires the CPU to constantly monitor peripheral devices.
Interrupt-Initiated I/O
This technique utilizes interrupts and commands
Read MoreDatabase Systems: A Comprehensive Guide to Design and Management
Database Systems
Introduction
A database is a structured collection of related data, while a database system (DBS) is the software that manages and interacts with the database. Database systems are essential for organizing and storing large volumes of data across various applications, ranging from small-scale systems to large enterprise solutions.
Data and Database Management Systems (DBMS)
Data represents recorded facts with implicit meaning. A Database Management System (DBMS) is a software package
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